1. Field of the Invention
The present invention relates generally to agricultural equipment, such as harvesters, and more specifically, to windrowing arrangements on such harvesters, and still more specifically to clean out of crop material from a windrower chute.
2. Description of the Related Art
An agricultural harvester known as a “combine” is historically termed such because it combines multiple harvesting functions with a single harvesting unit, such as picking, threshing, separating and cleaning. A combine includes a header which removes the crop from a field, and a feeder housing which transports the crop matter into a threshing rotor. The threshing rotor rotates within a perforated housing, which may be in the form of adjustable concaves, and performs a threshing operation on the crop to remove the grain. After the grain is threshed, it falls through perforations in the concaves onto a grain pan. From the grain pan, the grain is cleaned in a cleaning system, and is then transported to a grain tank onboard the combine. A cleaning fan blows air through the sieves to discharge straw, chaff and other debris toward the rear of the combine.
During the process of harvesting, crop material other than grain (MOG) is intended to be expelled from the combine. This material is usually derived from one of two areas in the combine, the threshing rotor or the cleaning system. The material expelled from the threshing rotor is generally referred to as straw, and the material expelled from the cleaning system is generally referred to as chaff. This material, or crop residue, typically is discharged from the combine by processes of either spreading or windrowing.
Spreading is accomplished using a mechanical device referred to as a spreader, which distributes the straw and/or chaff substantially evenly from the rear of the combine. Commonly, the spread material is chopped to as short a length as possible so that when the chopped material is spread onto the field it will break down quickly and not interfere with subsequent tilling or seeding operations.
Windrowing refers to the process of dropping straw directly behind the combine in a continuous stream, often substantially narrower than the combine cutting width. The purpose for windrowing is usually to facilitate post-harvest processing of the straw for uses other than incorporating the straw back into the field. For example, straw can be further processed by shaping it into bales that are removed from the field so that the straw can be used for other purposes such as, for example, animal feed or bedding, ground cover or mulch, or other purposes. When the straw is windrowed, it is known to allow the straw to pass through the combine with little interference and with little or no chopping, so that the straw remains as close as possible to its original length and condition.
U.S. Patent Application Publication Nos. 2015/0011275A1 and 2015/0011276A1 (which are assigned to the assignee of the present invention) disclose a spreader arrangement and actuation linkage mechanism therefor that simply and effectively allows both spreading and windrowing from the rear of the harvester. A selectively movable swath door at the upper rear of the straw hood is movable between a first position directing crop material to the spreader discs, and a second position directing crop material to a windrow chute. The windrow chute folds up and out of the way to the rear of the straw hood when the spreader arrangement is in the spreading mode, and is lowered to receive and direct the straw when windrowing is the desired handling process.
Although the windrow chute is substantially smooth and downwardly angled when in use, so that the straw and other material will slide easily along the chute, in some harvesting conditions the crop material can accumulate along the upper edge of the windrow chute. The long strands of straw can overhang the top edge of the chute, and can be pinned in a space between the edge of the windrow chute and adjacent structures of the harvester. When harvesting in moist conditions, either from atmospheric moisture or moisture in the crop itself, sticking of the crop material in the windrow chute can occur. If crop material is allowed to accumulate on the chute or at the upper edge of the chute, the continued buildup can cause malfunction of the windrower or perhaps even complete plugging.
To prevent problems associated with crop material buildup in the windrow chute, a person operating the combine can stop periodically to remove any accumulated crop material. However, this prolongs the harvesting operation, and may do so needlessly if little accumulation has occurred. Alternatively, the operator can wait until the accumulation is significant; however, this can make the cleaning process more difficult and time-consuming.
What is needed in the art is a procedure to clean a windrow chute of accumulated material, without interrupting or slowing the harvesting process.